The Argentine writer Jorge Luis Borges, who specialized in enigmatic fictions with improbable but believable twists, once wrote of a gaucho who had taken a bad spill from his horse and been paralyzed. Before the accident, Ireneo Funes had been “known for certain peculiarities such as avoiding contact with people and always knowing what time it was, like a clock.” Afterward, his mind became so crowded with memories and data—childhood visions, “the forms of the southern clouds at dawn on the 30th of April, 1882,” the “cases of prodigious memory” that Pliny records in his Natural History—that he could scarcely think. Which is to say, following Borges, “To think is to forget differences, generalize, make abstractions,” which is quite different from living in a world like the memorious Funes’s, in which there are only unique details.

As neuroscientists such as Oliver Sacks and Jerome Bruner have documented, many people inhabit such puzzling worlds. I would not claim to be one of them, but I have always had a solid memory for such things as historical dates, world capitals, actors in long-extinct films, lines of poetry read five decades ago, the layout of cities around the world—useful skills for an encyclopedist, to be sure. Less helpfully, and increasingly, I also have trouble putting certain names to certain faces, remembering whether I returned a call, keeping a shopping list of more than a couple of items in my head: the long term wins out more often than not, and the short term suffers.

Scientists at Columbia University Medical Center characterize this condition, discomfitingly, as “having too much memory,” which crowds out the immediate and impedes the formation, processing, and storage of short-term recall.

Strangely, according to a report published in the March 13, 2007, issue of the Proceedings of the National Academy of Sciences, the process called neurogenesis, the growth of new neurons in the hippocampus, seems to contribute to this mental obstacle course. Apparently, the absence of neurogenesis in the brain region that governs learning and memory allows a person (or, as in the study, a mouse) to remember where his or her keys are, or where his or her car is parked, or what he or she had for lunch.

The findings have implications for medicine, neuroscience, pharmacology, and other disciplines. Remarks researcher Gaël Malleret, “In medicine, these findings have significant implications for possible therapeutic interventions to improve memory; a careful balance of neurogenesis would need to be struck to improve memory without overwhelming it with too much activity.”

Of course, balancing out this neurogenesis means that long-term memory may suffer, which means that medical consumers may one day have to choose which they prefer: a working memory that makes finding the checkbook and cellphone easier, or a working memory of the absent-minded professor type that allows for recalling the chronology of the Roman emperors or the moods of the Sanskrit verb, but that may also mean a burned casserole along the way.

Poor Funes, the unacknowledged inspiration for the old Stanley Kesler/Charlie Feathers song “I Forgot to Remember to Forget”: neurogenesis proved his downfall. I’ll report back with further developments. If, that is, someone fires off a reminder for me to do so.